Global food giant Mars has launched a lawsuit against the Irish arm of German pet food maker Rondo in a battle over a $125m (€104m) market for dog treats.

The Irish firm and its German parent have been accused of trademark and patent infringement.

Mars, which owns a range of popular sweet brands from the eponymous chocolate bar to Wrigley's and M&M's, also owns some of the most recognisable pet food brands such as Whiskas, Cesar and Pedigree.

The family owned behemoth has fired the legal salvo at Rondo in Tennessee, where the headquarters of Mars Petcare is based.

In a complaint filed with the local district court, Mars and its Petcare subsidiary point out the group is the leading manufacturer of pet food sold in the United States.

The group said that among its best-known products is a canine dental treat called Greenies. The product is manufactured in the shape of a toothbrush.

Mars has told the US court it has earned more than $1bn (€837m) in revenue from the sale of the products, which clock up annual sales of about $125m. It added that it spends "tens of millions of dollars" advertising Greenies.

The company said in its legal complaint that Rondo - which employs more than 100 people at a major manufacturing base in Arklow, Co Wicklow - recently launched a competing line of dental treats.

"Rather than invest the time and resources to create their own trade dress, defendants simply helped themselves to the trade dress of plaintiffs' Greenies products, copying the toothbrush and dog-bone shape and duplicating the green colour of the products," Mars alleged in its complaint.

Mars claimed Rondo is selling its competing product, called Abound, to companies in the United States, "with actual knowledge that those the products are, in turn, advertised, distributed and resold to customers throughout the country".

Mars added the design patent for the configuration of the Abound product is owned by Rondo Ireland and claimed the alleged infringing products "are likely to cause confusion, mistake, or deception among consumers, including pet owners, as to the source and origin of the products".

The company has asked the Tennessee court for a jury trial and demanded a "reasonable royalty" from the sale of the Abound products, and further damages that should be trebled due to Rondo's alleged "wilful patent infringement".

Rondo's German office did not respond to a request for comment.

Rondo Food acquired the Gaines pet food company in 2011. Gaines had a presence in Ireland since 1995.

In 2013, Rondo relocated the group's manufacturing site in Arklow to South Quay in the town.

In 2016, it acquired the 50,000sqm rented premises on a 5.2 hectare site from Nama.

The Irish operation manufactures vegetarian snack products for dogs that are exported to North America, Asia and Australia.

The latest set of publicly available accounts for Rondo Food Ireland show it made a €249,000 loss in 2016, compared to a €963,000 loss in 2015.

It had an accumulated loss of €8.4m at the end of 2016.

The company did not reveal a revenue figure, but said turnover in Canada and the United States was higher during the year.

In 2016 the Arklow plant was hit by a warehouse fire that destroyed stock and equipment.

"The building and all stored packaging was completely destroyed and consequently the factory had to cease production," the accounts note.

The fire resulted in a €100,000 insurance claim and the factory returned to full production in January 2017.